PS1-10bzj: A Fast, Hydrogen-Poor Superluminous Supernova in a Metal Poor Host Galaxy

TL;DR

This paper reports on PS1-10bzj, a hydrogen-poor superluminous supernova with a less extreme luminosity than previous events, located in a low-metallicity, young dwarf galaxy, and explores possible powering mechanisms.

Contribution

It provides detailed observations and analysis of PS1-10bzj, including its light curve, host galaxy properties, and potential energy sources, expanding understanding of SLSNe in low-metallicity environments.

Findings

PS1-10bzj has a lower peak luminosity than similar SLSNe.

The host galaxy is a compact, low-metallicity dwarf with high specific star formation rate.

Both magnetar spin-down and circumstellar interaction models fit the supernova data.

Abstract

We present observations and analysis of PS1-10bzj, a superluminous supernova (SLSN) discovered in the Pan-STARRS Medium Deep Survey at a redshift z = 0.650. Spectroscopically, PS1-10bzj is similar to the hydrogen-poor SLSNe 2005ap and SCP 06F6, though with a steeper rise and lower peak luminosity (M_bol = -21.4 mag) than previous events. We construct a bolometric light curve, and show that while PS1-10bzj's energetics were less extreme than previous events, its luminosity still cannot be explained by radioactive nickel decay alone. We explore both a magnetar spin-down and circumstellar interaction scenario and find that either can fit the data. PS1-10bzj is located in the Extended Chandra Deep Field South and the host galaxy is imaged in a number of surveys, including with the Hubble Space Telescope. The host is a compact dwarf galaxy (M_B ~ -18 mag, diameter < 800 pc), with a low stellar mass (M_* ~ 2.4 * 10^7 M_sun), young stellar population (\tau_* ~ 5 Myr), and a star formation rate of ~ 2-3 M_sun/yr. The specific star formation rate is the highest seen in a SLSN host so far (~ 100 Gyr^{-1}). We detect the [O III]\lambda 4363 line, and find a low metallicity: 12+(O/H) = 7.8 +/- 0.2 (~ 0.1 Z_sun). Together, this indicates that at least some of the progenitors of SLSNe come from young, low-metallicity populations.